US election 2016: Hillary Clinton claims the Democratic presidential nomination, shattering 'hardest, highest' glass ceiling

'Barriers can come down. Justice and equality can win,' she said

Hillary Clinton has cemented her position as the presumptive Democratic nominee, seizing her place in history as the first woman to contest a US presidential election at the head of a major political party.

The former Secretary of State cruised to victory in four of the week's six state primaries including, crucially, California - where her rival, Bernie Sanders, had hoped to fuel his flagging campaign.

When she conceded defeat to Barack Obama at the end of a long and gruelling primary season in 2008, Ms Clinton expressed regret that she had been unable to “shatter that highest and hardest glass ceiling”, the presidential nomination. As she at last celebrated her 2016 primary triumph with supporters in Brooklyn on Tuesday night, she returned to the metaphor. "Barriers can come down. Justice and equality can win," she said. "This campaign is about making sure there are no ceilings, no limits on any of us. This is our moment to come together."

Describing her nomination as a “milestone”, Ms Clinton harked back to the history of women’s rights, including the Seneca Falls convention of 1848 and the passing of the 19th Amendment in 1919, which gave women the vote. “Tonight’s victory is not about one person,” she said. “It belongs to generations of women and men who struggled and sacrificed and made this moment possible.”

Ms Clinton was declared the winner of the races in the key state of California - by 56 per cent of the vote to Mr Sanders' 43 per cent – New Jersey, South Dakota and New Mexico, racking up delegates from the total of 694 that were in play at the day's primaries. Mr Sanders picked off victories in North Dakota and Montana.

On the eve of the votes, the Associated Press reported that Ms Clinton had already passed the threshold of 2,383 delegates needed to claim the nomination. That count comprised pledged delegates from primaries and caucuses, as well as superdelegates who will cast their votes at the Democratic convention in July, and who told the news agency they were already set on supporting Ms Clinton. The report caused outrage in the Sanders camp, which decried the media’s “rush to judgement,” pointing out that superdelegates “do not vote until July 25 and can change their minds between now and then.”

By this week, Ms Clinton was ahead of Mr Sanders by several states, close to 300 pledged delegates and some three million individual votes. Given her strong finish on Tuesday, she has now reached a majority of pledged delegates.

Addressing an emotional crowd at his California headquarters in Santa Monica, Mr Sanders insisted he would soldier on regardless, saying he intended to “fight hard" to win the final primary in Washington DC on 14 June, and then "take our fight for social, economic, racial and environmental justice" to the party convention in Philadelphia. “I know that the fight in front of us is a very, very steep fight," he said, "but I will continue to fight for every vote and every delegate we can get.”

Despite his decision not to drop out of the Democratic race, the Vermont Senator struck a conciliatory tone, saying he had received a “gracious” phone-call from Ms Clinton and congratulated her on her victories. And he had a defiant message for Donald Trump, saying “The American people will never support a candidate whose major theme is bigotry.”

In her speech, Ms Clinton commended Mr Sanders on what she said was an “extraordinary” campaign, acknowledging that he had “excited millions of voters, especially young people.” Insisting that she and the Vermont Senator agreed on the major issues, she called on his supporters to put aside their resentments ahead of the general election. “It never feels good to put your heart into a cause or a candidate you believe in and to come up short. I know that feeling well,” she said. “But as we look ahead to the battle that awaits, let’s remember all that unites us.”

Hillary Clinton celebrates clinching the Democratic presidential nomination with supporters in Brooklyn, New York (AP) ((AP))

Mr Trump, the presumptive Republican nominee, added to his haul of primary states with uncontested victories in New Jersey, California, New Mexico, Montana and South Dakota. Speaking to supporters at the Trump National Golf Club in Westchester, he intensified his attacks on his future general election opponent, accusing her of having “turned the State Department into a private hedge fund” during her tenure as Secretary of State.

Mr Trump's speech, delivered from a teleprompter, provided a taste of the ugly tactics to come in the general election. Implying that Ms Clinton had offered favourable treatment to dubious foreign powers in return for donations to her family foundation, the billionaire property mogul said Ms Clinton and her husband, former President Bill Clinton, had “turned the politics of personal enrichment into an art-form.”

Encouraging disaffected Sanders voters to come over to his side, Mr Trump said: “To all of those Bernie Sanders voters who have been left out in the cold by a rigged system of superdelegates, we welcome you with open arms.”

As she launched her campaign a year ago, faced with a ragbag of little-known competitors, Ms Clinton could have been forgiven for expecting a coronation. But while former governors such as Martin O’Malley and Lincoln Chafee failed to capture voters’ imaginations, it was Mr Sanders, a 74-year-old self-described socialist, who unexpectedly mounted the most resonant and resilient challenge to Ms Clinton – and to the status quo.

Mr Sanders only joined the Democratic party in 2015 after decades as an independent, and was at first considered little more than a protest candidate. But his revolutionary message quickly drew a loyal following that continued to grow as the race ground on. With a fundraising machine forged on social media, he was able to spend more than $200m on a campaign that has forced the front-runner and the Democratic establishment to the left on multiple issues.

The strength of the Sanders surge means that, even in defeat, his campaign has secured major concessions from the party, including five seats on the 15-person convention platform committee, which authors the Democratic policy platform for the general election.

But while the Vermont Senator has consistently outperformed Ms Clinton among younger voters and independents, he was unable to break her deep ties with the African-American community, particularly in the early voting states of the Deep South. Ms Clinton also overshadowed the outsider in major states with large Hispanic populations, such as New York, Texas and Florida.

The former Secretary of State landed her first blow of the general election last week, with a foreign policy speech in which she characterised Mr Trump as "dangerous" and "ignorant". Last night she reiterated her claim that the reality TV star was “temperamentally unfit” to occupy the Oval Office. “When he says, 'Let’s make America great again,' that is code for ‘Let’s take America backwards,’” she said, adding: “He has abused his primary opponents and their families, attacked the press for asking tough questions, denigrated Muslims and immigrants. He wants to win by stoking fear and rubbing salt in wounds.”

Ms Clinton has weaknesses of her own as a general election candidate: some of her supporters fear the spectre of past scandals, while liberal critics are suspicious of her centrist policy record, particularly in foreign affairs. Ms Clinton herself concedes that she is “not a natural politician” like her husband or her former foe, President Obama. Her candidacy is historic in more than one way – she has higher unfavourable poll ratings than any previous nominee in recent memory.

But concerned Democrats can seek consolation in another fact: Donald Trump’s unfavourables are higher still.